Some servers were down due to hardware maintenance. Mine was from 8am to 4pm on Sept 3rd. Server was down for me at 5am and there was no server for me. Server and game came back up sometime on the 3rd. This was the message displayed.."If your server is not starting properly or appearing in the server list, we suggest trying to restore a Map Save backup from the "Restore backup" page in the webinterface. Please choose a backup from a day/time when the server was working last. If you pick a save and it doesn't work, select the next one in the list until it works.
This did not work for me. Its stuck on "The Server will now restart..." infinitely. I force stopped the server as well. Tried restarting and loading backups and same thing.